Final answer:
The demise of the dinosaurs is supported by the discovery of a distinct iridium layer in sedimentary rock at the Cretaceous-Paleogene boundary and a large impact crater near the Yucatán Peninsula, pointing to a catastrophic asteroid impact that blocked sunlight and led to mass extinctions.
Step-by-step explanation:
Evidence for a meteorite strike leading to the demise of the dinosaurs includes an iridium layer in sediments found in the geological record. This iridium layer corresponds to the Cretaceous-Paleogene boundary and is not commonly found on Earth's surface, but is associated with extraterrestrial material such as meteorites. A large concentration of iridium detected in the geological strata marks the time when dinosaurs and many other species suddenly disappeared, supporting the theory of a catastrophic asteroid impact.
Furthermore, the discovery of a large impact crater near the Yucatán Peninsula with the appropriate age corroborates this hypothesis. In addition, the immediate aftermath of the collision included global climactic effects such as a cloud of debris that blocked sunlight, leading to the extinction of plants and animals that survived the initial impact.